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Dewster,The limitations of the 7bit 0-127 value system has been argued a lot over the last 20 years as electronic instruments have become more capable and expressive. From pianists to drummers (using electronic drums) countless people have argued that 127 values is nowhere near enough.

Casio is not the first to implement a 14-bit system on the keyboard. You will find this on products such as Yamaha Clavinova. I'm not aware of other manufacturers providing this level of detail on products under $1000. Needless to say, the keyboard's connection to the AiR sound source that I believe takes our product to another level.

Mike, I have a question: I am planning on getting the PX-350 as I am enjoying my P130 perhaps even a little more than the P95. I really liked the PX-830 and somewhat question why I didn't get it instead of the P95 2 years ago and it came down to portabililty.

Was any consideration given to perhaps having one of the portable models contain the 2 20 watt speakers? Or does this require a larger shell?

Anyway, maybe I'm over-simplifying, but it sounds like the keyboard sends 16k velocity levels to the board's internal piano sound engine rather than the more typical 127. Is there more to it than that? And do you think that's not valuable? I'm afraid I'm missing something...

To sense velocity from two positional switches, you need one timer per key. You start the timer when the upper switch closes, and stop it when the lower switch closes. The time elapsed is inversely proportional to the average velocity between switch events.

You have to take the elapsed time count and filter it in many ways. If the count is too high (too low velocity) the filter spits out the minimum velocity or zero velocity. If the count is is too low (too high velocity) the filter spits out the maximum velocity. In between these the filter might add an offset, apply a curve that favors the high end (harder) or low end (softer), etc.

For the filter to be able to spit out all possible values (with no missing output codes) the input elapsed time count must have more resolution than the output (since we're dealing with integers). So there is definitely a value in having more precision at the input of the filter. Is there a value in having more than 127 levels at the output of the filter? Mike is saying it is better to have more, but he's here selling Casio. I could be persuaded to believe more than 127 is good, but I would need a study. If Mike is saying it was non-trivial for Casio engineers to implement this, certainly they had some hard data driving them to commit the time, energy, and money required to do so?

I can certainly see situations where more output bits would be good, like if you are using the keys to trigger a PC sampler and want to apply a second velocity curve on the PC. I wonder if the new Casios can output this higher resolution velocity data via MIDI?

But more resolution to the internal sound generator? I'd need to be persuaded there is a real need for it.

there is definitely a value in having more precision at the input of the filter. Is there a value in having more than 127 levels at the output of the filter?

I still don't quite get the distinction.

Let's say the fastest velocity (represented by the speed at which the key would travel from the top sensor to the bottom sensor if a bowling ball were dropped on it... or as close to that as they could imagine any human managing in normal playing) is 1 millisecond. Let's say the slowest velocity which they think should produce any sound at all is 500 milliseconds (i.e. anything slower than that would be slow enough that, on a real piano, it would produce no sound).

(I know those numbers may bear no resemblance to reality; I know that some DPs produce a minimum sound no matter how long you take to depress the key... but I'm just choosing a range of number to illustrate.)

So we have a range of 500 milliseconds which need to be translated into either 127 values (where 1 millisecond = velocity 127 and each additional 4 milliseconds or so decreases that value by one); or we have 16,256 values where 1 millisecond = velocity 16,256, and each additional .03 millisecond decreases that value by one.

There is not a pre-filter division and a post-filter division; there is an absolute time, and a value derived from it. Though of course, they could apply a curve so that the division of time into velocity units is not so linear. But it's still a simple equation of time on one side and a velocity value to send to the tone generator (and/or over MIDI) on the other.

No?

EDIT: I think maybe I understand, you're talking about how fine the initial time measurement is... whether it's to the nearest millisecond, or something finer (or more coarse) than that, which also has to be represented digitally as some number of bits, yes? But processors have long worked with tiny increments of time, even a millisecond is long to a processor, and MIDI has no relevance to the time calculation (from triggering one sensor to the other). So I think the only place "increased definition" makes sense is on the other side of the equation.

No. For one thing you're equating subtraction with division. The elapsed time is inversely proportional to velocity.

An object traveling at 1 m/s will take one second to travel a meter, say this produces a count of 100. An object traveling twice as fast will take 1/2 second with a count of 50. And an object traveling three as fast will take 1/3 second with a count of 33.3. The velocities 1, 2, and 3 are equally spaced, but the elapsed time counts 100, 50, and 33.3 aren't. It's this cramping that requires increased input resolution to the velocity filter.

I didn't see you message before adding my edit, but it looks like my edit was on the wrong track anyway. ;-) I still don't really get this (i.e. "input resolution to the velocity filter") but I don't feel I have the background to continue to discuss this intelligently, so I'll leave it here.

Mike, I have a question: I am planning on getting the PX-350 as I am enjoying my P130 perhaps even a little more than the P95. I really liked the PX-830 and somewhat question why I didn't get it instead of the P95 2 years ago and it came down to portabililty.

Was any consideration given to perhaps having one of the portable models contain the 2 20 watt speakers? Or does this require a larger shell?

Also, is there any reason you would recommend a 150 over a 350?

I really like the PX-830 as well. Other than the PX-3 it was the only model that had the matte finished keys. 20w per side could be done in a "portable" slab but it would significantly add to the weight.

In regards to the PX-150 vs PX-350, my choice is the PX-350. There are many reasons why, but my favorite is the USB audio recording. When you sit down to play, just plug in a USB thumb drive and press the audio record button twice and it is recording a .wav file.

I recorded a very informal video in my office tonight of myself playing the PX-350. I didn't have to hook up the computer, dial up software or anything. It captured all the audio which I lined up with the video later. So convenient. Not sure if I'll post this yet....wasn't really happy with the way I played. I'll watch it again in a few and make up my mind about. Either way, I'll shoot more video tomorrow.

Mike,Will you be making a video demo of any of the new models or is Casio going to just be putting up audio samples of the new Privias? So it sounds like with the new action, the keystroke pressure will affect how the paino reproduces the note that is sounded and the nuance?

One thing I wanted to ask you was about the speakers- I feel as though the ones on the PX130 do a nice job of filling the room I am in and the piano sounds very similar with headphones on.

I also got one of those stereo miniplug cables to connect the 130 to my Mackie MR5's- and to be honest only did it once because I find that I am getting the sound I want from the keyboard itself- compliment to Casio for well designed speakers on their slab pianos.

That is my complaint about my P95 over time- it is a completely different instrument- I do not hear any attack on the internal speakers but with headphones to me I feel as though I am sitting at a grand.

Power being equal, how does having the tweeters on the 350 change the sound vs the 130 or even 150 ? Does it make it perceived as louder (with the same wattage) change the EQ?

The 850 looks great as well, but for me personally-I would be more inclined to get the 350 and put it on an x-stand and later add the custom cs-67.

Seems the 850 would come in a 100+pound box and it is just way easier for me the way my 95 and 130 came ups.

As you can tell I have the Yamaha custom stand and found it simpler to set up, easier to have shipped etc..

RE: the extra velocity resolution, I'm very much with Dewster on this one: I'd like to see a carefully controlled study.

My feeling is that these kinds of specs don't matter anyway. If the Casio sounds and feels good to play, what difference does it make whether it's because of the 16,000 velocity layers or not? Conversely, what if some study showed that extra velocity levels were indeed noticeable? That wouldn't mean that a model with that feature would necessarily sound better than a model without it, it would depend on the success of the implementation along with all the other variables that make one piano sound better than another. It may be interesting to know from an academic standpoint, but I can't see where it would be relevant in actually choosing what model to buy.

Mike,As I would like a console piano, I was wondering if the Privia PX-850 will be similar in action and piano sounds to the Celviano AP-650M, although I know the latter will have a greater number of sounds. I'm interested since it looks like I'd be able to try out the PX-850 fairly soon, as the AP-650M won't come out until January, and I wanted to try to get an early sense of what the AP-650M will be like. Just wondering if the AP-650M will be worth waiting for. I have liked the AP-620, but have found on a number of models that I have tried that the keys have some annoying lateral motion and the piano sounds die off a little too quickly for my taste (classical music).Thanks very much for all your info about Casio pianos.Steve

Other than that, a 350 is a 150 with more features, so it's a matter of whether you need the extra features. I would prefer the 350 for the Line Out jacks, the standard MIDI connectors, the extra sounds, and the ability to store registrations. But there are other differences that might matter more to someone else. If you don't need any of them, stick with the 150.

It may be interesting to know from an academic standpoint, but I can't see where it would be relevant in actually choosing what model to buy.

I don't see it as academic. A manufacturer is saying it makes a real difference - is that real science or just marketing? Though I'm pretty sure increased velocity resolution isn't the first thing I'd fix in a looped instrument...

If I want to record the sequence I'm working on, do I just load it to the USB thumb drive and turn off the keyboard? When I turn the keyboard back on, will the thumb drive then load the sequence I was working on so that I could continue working on it?

It may be interesting to know from an academic standpoint, but I can't see where it would be relevant in actually choosing what model to buy.

I don't see it as academic. A manufacturer is saying it makes a real difference - is that real science or just marketing? Though I'm pretty sure increased velocity resolution isn't the first thing I'd fix in a looped instrument...

Dewster,There was early question about "what else is different about the action". I did my best to address it. You can believe if you wish that it is just marketing but many manufacturers have developed higher resolution key triggering systems to allow more precise control over the expression on an electronic instrument. Casio I believe is the first to do this under $1000.

That being said, this is not the "first thing" that Casio did when developing the new series. The first thing was to develop a proprietary new processor that would allow better, control, providing damper resonance simulation, access larger memory sizes, provide better effects and much more.

If I want to record the sequence I'm working on, do I just load it to the USB thumb drive and turn off the keyboard? When I turn the keyboard back on, will the thumb drive then load the sequence I was working on so that I could continue working on it?

Marvin,The USB thumb drive does several different things. One of the things it can is audio recording. It is very simple, you arm it to record, you play and it creates a .wav file. You can do 99, 25 minute recordings. The USB drive can also serve as storage for the 17 track recorder. This is a multi-track system that Yes would allow you to work on a song piece by piece. The USB drive however is only used to save or backup your song as it stays in memory after you turn the PX-350 off.

I don't see it as academic. A manufacturer is saying it makes a real difference - is that real science or just marketing?

But all that matters is if it's good. If it is, it doesn't matter how they got there. If it isn't, it doesn't matter what features it has, and whether you can scientifically prove they're audible or not. That's why I say it's academic... the knowledge will in no way impact whether or not you will buy the piano, even though it may be interesting to know (which is pretty much the definition of it being academic).

Also, a scientific test could prove it can make an audible difference, it still wouldn't tell you whether or not it really makes a difference in this particular design. Or conversely, I suppose, a test could appear to show that more velocity levels makes no difference, but it may be hard to devise a test that could prove it could never make a difference in any circumstance, regardless of other design aspects of the tone or action of the piano, or for that matter, regardless of the player/listener (i.e. it is possible something may only be discernible by one in a hundred people, or one in a a thousand...).

(I also have a hard time imagining who would fund such an independent study, toward what end. But then, people do study all sorts of things...)

But speaking theoretically, in terms of sound, I have a hard time thinking it really makes much difference. The entire volume range of an acoustic piano is, I believe, maybe about 50 dB max. 127 volume levels, then, is enough for any two adjacent levels to be less than a half dB apart, which I believe is a difference below what most people can hear even in the "easiest" frequency and level range to notice differences, so it seems like finer resolution than that would not be audible.

But there are some other variables. Increased velocity doesn't merely change the level of a piano note, it can also change the timbre. But even a timbre increase is really only a level change, it is just that it is a non-linear change, i.e. the level of some harmonics change more than others. I'm not sure whether your ear may be able to pick up such non-linear level changes at finer amounts than when the entire harmonic spectrum of a sound changes in linear fashion, anyone know?

Another variable is that your fingers are capable of, in a sense, an infinite number of velocities. Even though you can't produce a specific velocity on demand (I doubt most people could do that even within only a range of 127, or even 50), you still (for example) "play through" a crescendo at various velocities you could not necessarily produce on demand, but they do need to correlate to particular sonic changes. So this, to me, is the other side of the argument. It's not a matter of hearing more than 127 distinct sounds, it's a matter of being able to naturally respond to the more than 127 different velocities we strike the keys with. In this case, any scientific test would not be based on whether a listener could discern the difference between hearing a 127 and 16k velocity piano, but whether the player could tell the difference in how it "felt" in terms of the sonic changes corresponding to his fingers.

Put differently, sonically, 127 "levels" may be sufficient, but there may be a benefit to mapping those levels to more than 127 "velocities" (and not necessarily in a linear fashion), and that would be hard to discern in any way other than the subjective experience of the player.

That said, I would tend to think that 127 "ranges" of velocities (even if differently "sized") should be enough... i.e. even if someone scientifically "proved" that 16,000 velocities were better than 127, I think it would be that much harder to prove that 16,000 velocities is better than any possible implementation of 127. That is, if the problem of insufficient velocity resolution exists at all, there may be more than one way to address it, so again, even proving that more velocities can be beneficial doesn't prove that they will be beneficial, either in an absolute sense in any particular design, or relative to other possible solutions to the problem.

Mike,You play very well. Thanks for posting this. I am looking forward to playing one of these when they hit the stores. I'll be able to compare it to the PX-575 (which I currently have and like very much). I hope Casio brings this one back at some point with the newer technology.

I'm not quite clear, Mike. Are you saying that even without the USB thumb drive in place, the PX-350 will retain a sequence in its own memory even when it's turned off?

Originally Posted By: Mike_Martin

Originally Posted By: Marvin Eight

If I want to record the sequence I'm working on, do I just load it to the USB thumb drive and turn off the keyboard? When I turn the keyboard back on, will the thumb drive then load the sequence I was working on so that I could continue working on it?

Marvin,The USB thumb drive does several different things. One of the things it can is audio recording. It is very simple, you arm it to record, you play and it creates a .wav file. You can do 99, 25 minute recordings. The USB drive can also serve as storage for the 17 track recorder. This is a multi-track system that Yes would allow you to work on a song piece by piece. The USB drive however is only used to save or backup your song as it stays in memory after you turn the PX-350 off.

BFB,Thanks for watching. As I mentioned at the end of the video the recording of the piano was made on the PX-350 itself. The PX-350 has a slot for a USB thumb drive and can make audio recordings directly to the USB drive.

BFB,Thanks for watching. As I mentioned at the end of the video the recording of the piano was made on the PX-350 itself. The PX-350 has a slot for a USB thumb drive and can make audio recordings directly to the USB drive.

thanks Mike- i actually pulled my post because i went back and reread the thread and figured that out...